Antioxidant activity in different fractions of tomatoes

The objective of this study was to determine the major antioxidants and antioxidant activity in different fractions (skin, seeds and pulp) of three tomato cultivars (Excell, Tradiro and Flavourine) grown under hydroponic conditions in a commercial greenhouse in New Zealand. It was found that the skin fraction of all cultivars had significantly (p < 0.05) higher levels of total phenolics, total flavonoids, lycopene, ascorbic acid and antioxidant activity (both in hydrophilic and lipophilic extracts as measured by the ABTS assay) compared to their pulp and seed fractions. The amount of antioxidants in each fraction was calculated on the basis of their actual fresh weights in whole tomato and it was found that the skin and seeds of the three cultivars on average contributed 53% to the total phenolics, 52% to the total flavonoids, 48% to the total lycopene, 43% to the total ascorbic acid and 52% to the total antioxidant activity present in tomatoes. These results show that removal of skin and seeds of tomato during home cooking and processing results in a significant loss of all the major antioxidants. Therefore, it is important to consume tomatoes along with their skin and seeds, in order to attain maximum health benefits.